/****************************************************************************

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** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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** contained in the Technology Preview License Agreement accompanying

** this package.

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** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

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****************************************************************************/

#include <QtGui/qpaintdevice.h>

#include <QtGui/qpixmap.h>

#include <QtGui/qwidget.h>

#include <QtCore/qdebug.h>

#include "qegl_p.h"

QT_BEGIN_NAMESPACE

// Current GL and VG contexts.  These are used to determine if

// we can avoid an eglMakeCurrent() after a call to lazyDoneCurrent().

// If a background thread modifies the value, the worst that will

// happen is a redundant eglMakeCurrent() in the foreground thread.

static QEglContext * volatile currentGLContext = 0;

static QEglContext * volatile currentVGContext = 0;

QEglContext::QEglContext()

    : apiType(QEgl::OpenGL)

    , dpy(EGL_NO_DISPLAY)

    , ctx(EGL_NO_CONTEXT)

    , cfg(0)

    , currentSurface(EGL_NO_SURFACE)

    , current(false)

    , ownsContext(true)

{

}

QEglContext::~QEglContext()

{

    destroy();

    if (currentGLContext == this)

        currentGLContext = 0;

    if (currentVGContext == this)

        currentVGContext = 0;

}

bool QEglContext::isValid() const

{

    return (ctx != EGL_NO_CONTEXT);

}

bool QEglContext::isCurrent() const

{

    return current;

}

// Open the EGL display associated with "device".

bool QEglContext::openDisplay(QPaintDevice *device)

{

    if (dpy == EGL_NO_DISPLAY)

        dpy = defaultDisplay(device);

    return (dpy != EGL_NO_DISPLAY);

}

// Choose a configuration that matches "properties".

bool QEglContext::chooseConfig

        (const QEglProperties& properties, QEgl::PixelFormatMatch match)

{

    QEglProperties props(properties);

    do {

        // Get the number of matching configurations for this set of properties.

        EGLint matching = 0;

        if (!eglChooseConfig(dpy, props.properties(), 0, 0, &matching) || !matching)

            continue;

        // If we want the best pixel format, then return the first

        // matching configuration.

        if (match == QEgl::BestPixelFormat) {

            eglChooseConfig(dpy, props.properties(), &cfg, 1, &matching);

            if (matching < 1)

                continue;

            return true;

        }

        // Fetch all of the matching configurations and find the

        // first that matches the pixel format we wanted.

        EGLint size = matching;

        EGLConfig *configs = new EGLConfig [size];

        eglChooseConfig(dpy, props.properties(), configs, size, &matching);

        for (EGLint index = 0; index < size; ++index) {

            EGLint red, green, blue, alpha;

            eglGetConfigAttrib(dpy, configs[index], EGL_RED_SIZE, &red);

            eglGetConfigAttrib(dpy, configs[index], EGL_GREEN_SIZE, &green);

            eglGetConfigAttrib(dpy, configs[index], EGL_BLUE_SIZE, &blue);

            eglGetConfigAttrib(dpy, configs[index], EGL_ALPHA_SIZE, &alpha);

            if (red == props.value(EGL_RED_SIZE) &&

                    green == props.value(EGL_GREEN_SIZE) &&

                    blue == props.value(EGL_BLUE_SIZE) &&

                    (props.value(EGL_ALPHA_SIZE) == 0 ||

                     alpha == props.value(EGL_ALPHA_SIZE))) {

                cfg = configs[index];

                delete [] configs;

                return true;

            }

        }

        delete [] configs;

    } while (props.reduceConfiguration());

#ifdef EGL_BIND_TO_TEXTURE_RGBA

    // Don't report an error just yet if we failed to get a pbuffer

    // configuration with texture rendering.  Only report failure if

    // we cannot get any pbuffer configurations at all.

    if (props.value(EGL_BIND_TO_TEXTURE_RGBA) == EGL_DONT_CARE &&

        props.value(EGL_BIND_TO_TEXTURE_RGB) == EGL_DONT_CARE)

#endif

    {

        qWarning() << "QEglContext::chooseConfig(): Could not find a suitable EGL configuration";

        qWarning() << "Requested:" << props.toString();

        qWarning() << "Available:";

        dumpAllConfigs();

    }

    return false;

}

// Create the EGLContext.

bool QEglContext::createContext(QEglContext *shareContext, const QEglProperties *properties)

{

    // We need to select the correct API before calling eglCreateContext().

#ifdef EGL_OPENGL_ES_API

    if (apiType == QEgl::OpenGL)

        eglBindAPI(EGL_OPENGL_ES_API);

#endif

#ifdef EGL_OPENVG_API

    if (apiType == QEgl::OpenVG)

        eglBindAPI(EGL_OPENVG_API);

#endif

    // Create a new context for the configuration.

    QEglProperties contextProps;

    if (properties)

        contextProps = *properties;

#if defined(QT_OPENGL_ES_2)

    if (apiType == QEgl::OpenGL)

        contextProps.setValue(EGL_CONTEXT_CLIENT_VERSION, 2);

#endif

    if (shareContext && shareContext->ctx == EGL_NO_CONTEXT)

        shareContext = 0;

    if (shareContext) {

        ctx = eglCreateContext(dpy, cfg, shareContext->ctx, contextProps.properties());

        if (ctx == EGL_NO_CONTEXT) {

            qWarning() << "QEglContext::createContext(): Could not share context:" << errorString(eglGetError());

            shareContext = 0;

        }

    }

    if (ctx == EGL_NO_CONTEXT) {

        ctx = eglCreateContext(dpy, cfg, 0, contextProps.properties());

        if (ctx == EGL_NO_CONTEXT) {

            qWarning() << "QEglContext::createContext(): Unable to create EGL context:" << errorString(eglGetError());

            return false;

        }

    }

    return true;

}

// Destroy an EGL surface object.  If it was current on this context

// then call doneCurrent() for it first.

void QEglContext::destroySurface(EGLSurface surface)

{

    if (surface != EGL_NO_SURFACE) {

        if (surface == currentSurface)

            doneCurrent();

        eglDestroySurface(dpy, surface);

    }

}

// Destroy the context.  Note: this does not destroy the surface.

void QEglContext::destroy()

{

    if (ctx != EGL_NO_CONTEXT && ownsContext)

        eglDestroyContext(dpy, ctx);

    dpy = EGL_NO_DISPLAY;

    ctx = EGL_NO_CONTEXT;

    cfg = 0;

}

bool QEglContext::makeCurrent(EGLSurface surface)

{

    if (ctx == EGL_NO_CONTEXT) {

        qWarning() << "QEglContext::makeCurrent(): Cannot make invalid context current";

        return false;

    }

    // If lazyDoneCurrent() was called on the surface, then we may be able

    // to assume that it is still current within the thread.

    if (surface == currentSurface && currentContext(apiType) == this) {

        current = true;

        return true;

    }

    current = true;

    currentSurface = surface;

    setCurrentContext(apiType, this);

    bool ok = eglMakeCurrent(dpy, surface, surface, ctx);

    if (!ok)

        qWarning() << "QEglContext::makeCurrent():" << errorString(eglGetError());

    return ok;

}

bool QEglContext::doneCurrent()

{

    // If the context is invalid, we assume that an error was reported

    // when makeCurrent() was called.

    if (ctx == EGL_NO_CONTEXT)

        return false;

    current = false;

    currentSurface = EGL_NO_SURFACE;

    setCurrentContext(apiType, 0);

    // We need to select the correct API before calling eglMakeCurrent()

    // with EGL_NO_CONTEXT because threads can have both OpenGL and OpenVG

    // contexts active at the same time.

#ifdef EGL_OPENGL_ES_API

    if (apiType == QEgl::OpenGL)

        eglBindAPI(EGL_OPENGL_ES_API);

#endif

#ifdef EGL_OPENVG_API

    if (apiType == QEgl::OpenVG)

        eglBindAPI(EGL_OPENVG_API);

#endif

    bool ok = eglMakeCurrent(dpy, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);

    if (!ok)

        qWarning() << "QEglContext::doneCurrent():" << errorString(eglGetError());

    return ok;

}

// Act as though doneCurrent() was called, but keep the context

// and the surface active for the moment.  This allows makeCurrent()

// to skip a call to eglMakeCurrent() if we are using the same

// surface as the last set of painting operations.  We leave the

// currentContext() pointer as-is for now.

bool QEglContext::lazyDoneCurrent()

{

    current = false;

    return true;

}

bool QEglContext::swapBuffers(EGLSurface surface)

{

    if(ctx == EGL_NO_CONTEXT)

        return false;

    bool ok = eglSwapBuffers(dpy, surface);

    if (!ok)

        qWarning() << "QEglContext::swapBuffers():" << errorString(eglGetError());

    return ok;

}

// Wait for native rendering operations to complete before starting

// to use OpenGL/OpenVG operations.

void QEglContext::waitNative()

{

#ifdef EGL_CORE_NATIVE_ENGINE

    eglWaitNative(EGL_CORE_NATIVE_ENGINE);

#endif

}

// Wait for client OpenGL/OpenVG operations to complete before

// using native rendering operations.

void QEglContext::waitClient()

{

#ifdef EGL_OPENGL_ES_API

    if (apiType == QEgl::OpenGL) {

        eglBindAPI(EGL_OPENGL_ES_API);

        eglWaitClient();

    }

#else

    if (apiType == QEgl::OpenGL)

        eglWaitGL();

#endif

#ifdef EGL_OPENVG_API

    if (apiType == QEgl::OpenVG) {

        eglBindAPI(EGL_OPENVG_API);

        eglWaitClient();

    }

#endif

}

// Query the value of a configuration attribute.

bool QEglContext::configAttrib(int name, EGLint *value) const

{

    return eglGetConfigAttrib(dpy, cfg, name, value);

}

// Retrieve all of the properties on "cfg".  If zero, return

// the context's configuration.

QEglProperties QEglContext::configProperties(EGLConfig cfg) const

{

    if (!cfg)

        cfg = config();

    QEglProperties props;

    for (int name = 0x3020; name <= 0x304F; ++name) {

        EGLint value;

        if (name != EGL_NONE && eglGetConfigAttrib(dpy, cfg, name, &value))

            props.setValue(name, value);

    }

    eglGetError();  // Clear the error state.

    return props;

}

// Initialize and return the default display.

EGLDisplay QEglContext::defaultDisplay(QPaintDevice *device)

{

    static EGLDisplay dpy = EGL_NO_DISPLAY;

    if (dpy == EGL_NO_DISPLAY) {

        dpy = getDisplay(device);

        if (dpy == EGL_NO_DISPLAY) {

            qWarning() << "QEglContext::defaultDisplay(): Cannot open EGL display";

            return EGL_NO_DISPLAY;

        }

        if (!eglInitialize(dpy, NULL, NULL)) {

            qWarning() << "QEglContext::defaultDisplay(): Cannot initialize EGL display:" << errorString(eglGetError());

            return EGL_NO_DISPLAY;

        }

#ifdef EGL_OPENGL_ES_API

        eglBindAPI(EGL_OPENGL_ES_API);

#endif

    }

    return dpy;

}

// Return the error string associated with a specific code.

QString QEglContext::errorString(EGLint code)

{

    static const char * const errors[] = {

        "Success (0x3000)",                 // No tr

        "Not initialized (0x3001)",         // No tr

        "Bad access (0x3002)",              // No tr

        "Bad alloc (0x3003)",               // No tr

        "Bad attribute (0x3004)",           // No tr

        "Bad config (0x3005)",              // No tr

        "Bad context (0x3006)",             // No tr

        "Bad current surface (0x3007)",     // No tr

        "Bad display (0x3008)",             // No tr

        "Bad match (0x3009)",               // No tr

        "Bad native pixmap (0x300A)",       // No tr

        "Bad native window (0x300B)",       // No tr

        "Bad parameter (0x300C)",           // No tr

        "Bad surface (0x300D)",             // No tr

        "Context lost (0x300E)"             // No tr

    };

    if (code >= 0x3000 && code <= 0x300E) {

        return QString::fromLatin1(errors[code - 0x3000]);

    } else {

        return QLatin1String("0x") + QString::number(int(code), 16);

    }

}

// Dump all of the EGL configurations supported by the system.

void QEglContext::dumpAllConfigs()

{

    QEglProperties props;

    EGLint count = 0;

    if (!eglGetConfigs(dpy, 0, 0, &count) || count < 1)

        return;

    EGLConfig *configs = new EGLConfig [count];

    eglGetConfigs(dpy, configs, count, &count);

    for (EGLint index = 0; index < count; ++index) {

        props = configProperties(configs[index]);

        qWarning() << props.toString();

    }

    delete [] configs;

}

QString QEglContext::extensions()

{

    const char* exts = eglQueryString(QEglContext::defaultDisplay(0), EGL_EXTENSIONS);

    return QString(QLatin1String(exts));

}

bool QEglContext::hasExtension(const char* extensionName)

{

}

QEglContext *QEglContext::currentContext(QEgl::API api)

{

    if (api == QEgl::OpenGL)

        return currentGLContext;

    else

        return currentVGContext;

}

void QEglContext::setCurrentContext(QEgl::API api, QEglContext *context)

{

    if (api == QEgl::OpenGL)

        currentGLContext = context;

    else

        currentVGContext = context;

}

QT_END_NAMESPACE